1. Field of the Invention
The present invention relates to a modular jack which is mounted in a device such as a notebook personal computer etc. and in which a corresponding modular plug is fitted.
2. Discussion of Background
Usually, a notebook personal computer is provided with a modular jack for coupling a modular plug from a telephone line.
This modular jack is provided with a resin casing having an insertion concave portion into which the modular plug is inserted and from which the modular plug is removed.
In recent years, although it is desired to miniaturize and make thin the notebook personal computer, since the modular plug is uniquely determined in its configuration and size in accordance with the standard, the size of the insertion and removal concave portion of the modular jack can not be changed.
Thus, in the case of miniaturizing the modular jack, the resin casing is inevitably required to be thinned in its thickness. However, in this case, there arises a problem that the strength of the resin casing becomes insufficient.
Accordingly, the invention has been made in view of the aforesaid problem of the conventional technique and an object of the invention is to provide a modular jack which is small in size and thin in thickness and has sufficient strength.
In order to attain the aforesaid object, a modular jack according to the invention is characterized by including a jack body for opening an insertion concave portion in a forward direction in which a modular plug having a plug body and an engagement lever of a cantilever fashion is inserted and from which the modular plug is removed, wherein the jack body includes a resin casing having a first side wall with an engagement portion and a second side wall for holding a contact pin, and a metal shell which covers a part of external surface of the resin casing and is fixed to the resin casing, and wherein the insertion concave portion is defined by a part of the metal shell in correspondence to upper and lower surfaces of the plug body.
According to the invention, for example, most of the upper and lower walls of the resin casing of the modular jack is eliminated and the upper and lower surfaces of the insertion concave portion are defined by the metal shell; therefore, the height of the modular jack can be lowered to the limit value. Further, since the resin casing is reinforced by the metal shell, the modular jack can ensure high strength despite that it is small in size and thin in thickness.
Preferably, the metal shell is arranged in a rectangular annular shape so as to surround periphery of the resin casing. In this case, since the metal casing surrounds the periphery of the resin casing to reinforce the resin casing, higher strength can be ensured.
Further preferably, the resin casing is arranged in a two-piece structure having a first resin casing with the first side wall and a second resin casing with the second side wall. According to this configuration, in the case of defining the upper and lower surfaces of the insertion concave portion by the metal shell, when the resin casing is arranged in a two-piece structure separated in the left and right portions, the thickness of the resin casing can be reduced remarkably, which contributes to the miniaturization and thinning of the modular jack to a large extent.
In addition, a rear surface of the jack body preferably includes an opening portion which introduces a base end portion of the engagement lever in a state where the modular plug is disposed at a deepest pushed position.
According to the modular plug as a standardized goods, the base end portion of the engagement lever is disposed at the most protruded position on the insertion side of the modular plug. In contrast, according to the invention thus configured, the base end portion of the engagement lever disposed at the deepest pushed position is introduced to the opening portion so that the base end portion and the rear surface of the jack body can be almost aligned on the same plane, whereby the depth of the jack body can be minimized as small as possible. According to this feature, the modular jack also can be miniaturized.